Polysaccharide from Ziziphus jujuba fruit protects ulcerative colitis mice via IL-33/ST2 signal Axis

Jujube is a medicinal herb and daily food. Polysaccharides extracted from jujube possesses immune regulatory activity. In this study, we investigated whether jujube polysaccharides (JP) could ameliorate ulcerative colitis (UC), an inflammatory disease, and explore the potential mechanism of UC. We first extracted and characterized the structure JP, using dextran sulfate sodium-induced UC mice model to verify the pharmacological function. Research proved that JP treatment could ease UC mice symptoms and pathological injury. According to transcriptomics analysis, majority genes were enriched to cytokines-cytokines receptors signal pathway. Results showed that the increasing proinflammatory cytokines in UC mice colon were declined after JP intervention. Meanwhile, the receptor of interleukin-33 (IL-33), tumorigenicity 2 suppression (ST2) and downstream protein MYD88 expression in UC mice colon were corrected by JP intervention. As a result, according to immunohistochemistry detection, JP downregulated UC mice colon T cells expression (labeled by CD3+). We further employed flow cytometry to validate that JP could suppress CD4+ high expression on Jurkat cell stimulated by IL-33. In conclusion, JP could ameliorate UC mice symptoms, the mechanism of which was related to the regulation of IL-33/ST2 axis.